In general, the objective of operation control of conventional group management systems is to reduce the average waiting time of passengers in elevators by efficiently controlling the operation of a plurality of elevators within a building.
Therefore, what the group management system must truly evaluate in its control operation is that the waiting time of passengers, including prospective passengers, and the significance of waiting time of individual passengers should be basically considered to be equivalent. However, a group management system has difficulty in directly figuring out the waiting time of individual passengers. Accordingly, the control operation is conventionally performed by evaluating the waiting time of a hall call as an alternative, that is, evaluating a time period as waiting time from a hall call is registered until an elevator arrives in response to the call.
Further, when evaluating, a focus of the evaluation is placed on the waiting time of a newly registered hall call as a target of assignment, and the waiting time of individual hall calls is not treated equivalently. In addition, as an assignment of a hall call affects, not only a call that has already been made but also a hall call that is possibly made in the near future, it is essential that the evaluation includes any hall call that may be made in the future. However, even if a hall call that is possibly made in the future is evaluated, an evaluation value for the call is usually treated only as a correction term (e.g., Patent Publication 1).
On the other hand, the conventional group management system is typically based on an “immediate assignment method” which determines a car to respond instantly upon registration of a hall call, and an “immediate prediction method” of which announces an assigned car instantly at an elevator hall. In a group management system employing the “immediate prediction method”, as any change in an assignment of a hall call that has been made may cause confusion among passengers waiting for an elevator, it is desirable not to change the assignment if circumstances allow. Accordingly, the assignment change is limited to a case satisfying specific conditions, such as changing an assignment of a potentially long waiting hall call to a different car (e.g., Patent Publication 2).
Further, the conventional group management system is provided with controlling means for moving a car to a random floor by assigning a pseudo call (virtual call) to the car. However, such means are used only under limited traffic situations such as distributed waiting during down peak and reference floor recalling when people arrive before working hours (e.g., Patent Publication 3).
Moreover, development of the conventional group management systems has been promoted in the policy of reducing waiting time of the hall call as much as possible with the application of artificial intelligence technologies such as “fuzzy” and “neuro” (e.g., Patent Publication 4).